The subject application relates generally to stalk rolls for row units for use with agricultural harvesters. In particular, the subject application relates to a pair of stalk rolls each having a helical flight wherein one helical flight is axially displaced relative to the other in order to provide efficient processing of crop stalks therebetween.
Agricultural harvesters provide for efficient harvesting of crops such as corn. When configured for corn harvesting an agricultural harvester generally includes a corn header which separates crop material (i.e., ears of corn) from corn stalks. The removed ears of corn are fed into a separator which separates the grains of corn from all other materials other than grain (“MOG”). A typical corn header includes several row units, one for each row being harvested in a single pass over a field. As the corn header moves forward, a corn plant in each row of corn enters the forwardly extending channel defined by the particular row unit associated with that row. Generally each row unit includes a stripping plate with a gap (“stripping plate gap”) that is wide enough to receive the corn stalk, but not wide enough for the ear of corn on the stalk to pass through. As the harvester moves forward, the stripping plates exert a backward and upward force on the ear of corn while the row unit stalk rolls pull the corn downwardly.
Below the stripping plate in each corn header unit are a pair of stalk rolls that are positioned on each side of the stripping plate gap. In a typical configuration a stalk roll is made up of a stalk roll spiral and a back section. The stalk roll spiral has helical flights that extend from a central cylinder. The back section extends rearwardly from stalk roll spiral. The stalk rolls are aligned so that the axes of the stalk rolls are parallel to the stripping plate gap. Typically the stalk rolls rotate in opposite directions to exert a downward and rearward force on the stalk relative to the stripping plate. The generally opposing forces exerted by the stalk rolls and stripping plates on the stalk and ear respectively act to separate the ear of corn from the stalk. The ears and any MOG are transported into the harvester or combine for further processing while the stalk generally remains rooted in the ground.